Medical personnel (e.g. radiologists) examine mammography images to diagnose various abnormalities in a breast. When examining these images within a viewing area on a mammography system, medical personnel desire to review the mammography image displaying a breast (i.e. the breast image), with little regard to any of the background. Also, as medical personnel are primarily interested in the breast area, it is highly desirable to extract this breast area and display it at an optimal and consistent scale across all displayed images. That is, medical personnel seek mammography systems that facilitate quickly generated diagnostic reviews of mammography images, and allow for convenient navigation and review between views of a medical imaging data set while maintaining the same presentation state, including for example the scale factor, across all of the images in the views.
Medical personnel have typically used the zooming and panning functionality of a mammography system. Specifically, once the user has positioned the mouse on a part of the mammography image that the user wants to focus on, using the zooming and panning functionality of the mammography system. Doing so for each successive image is time-consuming and inconvenient.
More efficient diagnostic review of mammography images has been facilitated through the use of a breast window. A breast window for a breast image is considered to be the smallest region that encloses all of the tissue points of a breast shown on mammography image. A breast window may be characterized by the size of the region as well as the location of the region within the mammography image. The mammography system may also define a breast window that contains an optimal part of a breast image and displays it optimally scaled (herein referred to as a “pre-scaled image”) such that the defined breast window fills the entirety of the viewing area of the mammography system. Use of a breast window can eliminate the time-consuming and inconvenient process of manual adjustment which may require re-iterative zooming and panning for each image within a plurality of mammography images.
Traditionally, older modalities, such as x-ray or magnetic resonance tomography, have produced individual mammography images that are two-dimensional images. A plurality of mammography images from a single modality may be considered to be an image series (also referred to as a series of mammography images).
Newer modalities, such as x-ray tomosynthesis or computed tomography imaging modalities, produce “volume-based” mammography images, which for example, may comprise a plurality of two-dimensional images stacked in series. Volume-based images are generated by first, processing traditional two-dimensional images to render additional images which may show the breast at different angles. These images are then used to generate the volume-based images in an image series. Medical personnel may view all images of an image series together by generating an overview image, or by obtaining an overview image from a modality. Wherein the overview image shows all or a subset of, tissue points from each image in the image series on a single two-dimensional image.
Current solutions that utilize breast windows typically identify a region of interest within each mammography image by processing each image. Next, the best scaling factor is determined and then mammography image is displayed using an individually calculated “scale to fit” factor. The result is that medical personnel cannot rely on the visual appearance of an anatomical element within a mammography image. To overcome this uncertainty it is necessary for the user to use manual display functionality through the graphical user interface to assess size characteristics of the anatomical element. This process is even more disruptive to the workflow than the system adjustments (i.e. zoom and pan) which the breast window-based solutions were aimed to replace. To address this, some mammography systems process the breast window for each image to be displayed to determine the common scale factor. The common scale factor then applied to all images in the series. This approach eliminates the need for manual zoom and pan, but requires time to process each image and determine the corresponding breast window, which impacts procedural efficiency of breast screening by mammography.
While current solutions are effective when applied to conventional mammogram image studies where a study is composed of individual mammography images. Current solutions are far less desirable for use with a volume based series of mammography images. Every time a new mammography image is added or viewed a new breast window needs to be calculated and there is an inherent delay before the optimal view can be displayed.
Overall the processing requirements behind the calculation of breast windows for each image in an image series creates significant processing and performance demands over the course of reviewing an image series. As a result, the cumulative time in which medical personnel may wait for the processor to render pre-scaled images can be very time-consuming and inconvenient, particularly in regards to mammography screening workflow. As new modalities continue to generate larger image data, the greater processing demands may decrease reliability and increase hardware infrastructure costs. There is a need for a mammographic system that provides more efficient review and navigation of an image series.